Valves



May 1, 1962 T. w. BU NYAN 3,032,068

VALVES Filed Jan. 22, 1959 L0 -BY Mmm A T TORNE) Unite The present invention relates to improvements in valves and in particular to control mechanism for a valve of the kind operated with the aid of a guided rod or stem.

It is an object of the present invention to provide a simple and reliable valve control mechanism utilising fluid pressure to effect movements of the valve.

In accordance with the invention there is provided a control mechanism for a guided rodor stem-operated valve, said mechanism comprising a cylinder having the operating rod or stem extending axially therethrough and a main piston fixedly mounted on the operating rod or stem and movable in the cylinder by fluid pressure between a first position in which the valve is fully closed and a second position in which the valve is fully open, and an abutment piston also movable in the cylinder by fluid pressure and between two positions, one an operative position in which it constitutes an abutment limiting the range of movement permitted to the main piston to a distance corresponding to that between its first valveclosed position and a third position corresponding to a partially open or cracked position of the valve, and the other an inoperative position in which the abutment piston permits unrestrained movement of the main piston into its said second position corresponding to the fully open position of the valve.

The valve and the improved control mechanism therefor is particularly suitable for inclusion in valve chests as employed on ships for example for controlling the flow of alternative liquids i.e. fuel oil, ballast-water or liquid-cargo required to be pumped into and withdrawn from a tank.

Such a valve chest comprises three chambers, one connected to the ballast-water or liquid-cargo lines, a second connected to the fuel-oil line and the third being connected with the interior of the tank, one valve being provided to connect the first and third chambers and another valve to connect the second and third chambers.

In the application of the present invention to such a valve chest the first and second chambers may be symmetrically disposed on opposite sides of the third chamber with two valve apertures formed one on each of two parallel opposite walls of the'third chamber and giving communication respectively with the first and second chambers. Two similar valves with stems are mounted in axial opposition with the stems movable in glands in the outer walls of the first and second chambers with extensions of the stems extending into cylinder and piston assemblies as described above fixed to the exterior of each of the same two outer Walls, for control of the respective valves through the stems thereof.

Means may be provided to prevent inadvertent application of fluid operating pressure to the control cylinder of either one of the valves to open it whilst the other valve is open.

Means may also be provided to enable the valves to be opened and closed by hand e.g. in the event of breakdown in the operating fluid pressure supply.

In the preferred arrangement return springs are provided in the control mechanism for each valve biasing the valves towards the closed position and such that the valves will be caused to close in the event of failure of the operating fluid pressure during operation of the valve chest.

atet

The invention is illustrated by way of example in the accompanying drawing as applied to a valve chest for use on board ship and which for convenience in description it will be assumed is used to control the introduction or removal of fuel-oil into or from a tank and the introduction or removal of ballast-water into or from the same tank when empty of fuel-oil.

FIG. 1 is a view in sectional side ele ation of a complete valve chest embodying the invention.

FIG. 2 is a view on an enlarged scale showing a detail of one of the valves associated with the valve chest.

Referring to the drawing the main body of the valve chest is formed to define three chambers 1, 2 and 3, the chamber 1 being connected through a port 4 with the ballast-water line, the chamber 2 being connected through a port 5 with the fuel-oil line and the chamber 3 being connected through a port 6 with the tank (not shown).

The chambers 1 and 2 are of similar configuration and are symmetrically disposed with reference to chamber 3 and each has one wall 7 or 8 in common with chamber 3.

The walls 7 and 8 are parallel and provided with circular valve apertures with seatings 9 and Ill.

The valves 11 and 12 are mushroom-headed valves mounted at the outer sides of the walls 7 and 8 and with their stems 13, 14 in axial alignment and sliding in glands 15, 16 in detachable parts 17, 18 of the outer walls of the chambers 1 and 2.

The glands 15, 16 may with advantage be formed each of two spaced parts as shown, the spaces between the parts being vented to atmosphere by way of passages 61 and 62 in the detachable parts 17 and 13.

To the outside of each of the outer walls 17, 18 are aflixed similar closed and axially aligned cylinders 19 and 2t}, and extensions 21 and 22 of the valve stems 13 and 14 slide in glands 23, 24 in the cylinder heads 25, 26 and project at the exterior thereof.

Main pistons 27, 28 are fixed e.g. by screwing as shown, on the stems 13, 14 of the valves in working positions in the lower halves of the two cylinders 19, 20 ie the ends of the cylinders nearer the walls of the chambers l and 2.

The main pistons 27, 28 are spring-loaded towards the :losed position by compression springs 29, 39 extending )etween shoulders on the pistons 27, 23 and annular abutment rings 31, 32 anchored in circumferential grooves formed in the walls of the cylinders.

Secondary or abutment pistons 33, 34 are mounted in working positions in the upper ends of the cylinders 19, 20 i.e. the ends remote from the walls of the chambers 1 and 2, and are capable of sliding on the extensions 21 and 22 of the valve stems 13 and 14.

Sets of three ports 35, 36 and 37 and 33, 39 and 40 are provided in the wall of each cylinder 19 and 20 for the selective introduction of working pressure fluid (air or hydraulic) from a common source into the spaces 41 and 42 between the main pistons 27, 28 and the lower ends of the cylinders, the spaces 43 and 44 between the main pistons 27, 28 and the abutment pistons 33, 34, and the spaces 45, 46, between the abutment pistons and the heads 25, 26 of the cylinders by means of a remote control of a conventional form (not shown).

To the outer sides of the cylinder heads 25 and 26 are fixedly connected extension members 47 and 48 bored for the sliding reception of the ends of the extensions 21, 22 of the valve stems 13, 14.

The extension members 47, 48 are machined internally to form two annular recesses 49, 50 (see FIG. 2) communicating with externally accessible ports 51 and 52.

The extensions 21 and 22 of the valve stems are each provided with a stopped axial bore 53 and two spaced sets of radial holes 54 leading from the bore 53, the spacing of the two sets of radial holes being such that each set registers with one of the annular recesses 49, 50 when the related valve 11 or 12 is fully closed, so that direct communication is afforded under this condition of a valve between the two ports 51 and 52 by way of the annular recesses 49, St the radial holes 54 and the closed axial bore 53.

One of the externally accessible ports 51 of each of the extension members 47, 48 is connected through a pipe with the source of operative fluid pressure.

The other externally accessible port 52 of the extension member 47 traversed by the extension 21 of the stem 13 of the valve 11 is connected by a pipe with the port 38 leading to the space between the main piston 28 and the bottom of the cylinder corresponding to the other valve 12, and the externally accessible port 52 of the extension member 48 traversed by the extension 22 of the stem 14 of the valve 12 is connected by a pipe with the port leading to the space between the main piston 27 and the bottom of the cylinder 19.

With this arrangement operating pressure fluid cannot be applied to the lower side of either of the main pistons 27 or 28 to open either of the valves 11 or 12 unless the other valve 12 or 11 is in its closed position.

Means are provided to enable the valves to be moved by hand when convenient or in the event of breakdown of the operative fluid pressure supply.

The means for this purpose comprises yokes 55 pivot'ally mounted near the ends of the cylinders 19 and 2t) and normally resting in a downwardly inclined position as shown away from the path of movement of the ends of the end extensions 21 and 22 of the valve stems 13, 14. The yokes 55 form carriers for screw rods 56 rotatable in screw bearings 57 on the yokes by means of hand- Wheels 58. Collar bushes 59 are provided on the free ends of the screw rods 56 for engagement in circumferential grooves 60 on the projecting ends of the valve stem extensions 21, 22, when the yokes are raised to a horizontal position, so that the valves may be opened and closed by rotation of the handwheels 58.

The normal operation is as follows:

Assuming the tank is being used for fuel oil and fuel oil is to be introduced or withdrawn, the valve 12 is required to open, and conditional upon valve 11 being in the closed position and the holes 54 in the stern extension 21 of valve 11 therefore in register with the annular recesses 49, 50 on the extension member 47, air or other operative fluid from the compressed fluid line is introduced through the port 38 to the space 42 in the cylinder 20 below main piston 28 so that the piston 28 is moved against the spring 30 to move the valve 12 to its full open position to put chamber 2 into communication with chamber 3 and fuel oil can now be pumped into or out from the chamber. When the flow of fuel oil is to cease compressed air or other fluid is introduced by way of port into the space 46 in the cylinder 20 above the abutment piston 34 and the pressure on abutment piston 34 being added to that of the spring 30 the main piston 28 and the valve 12 are moved towards the closed position to an extent determined by the engagement of the abutment piston 34 with the abutment ring 32, the valve 12 thus coming to rest in a partially open or so-called crack position thereby avoiding the shock which would be encountered by too rapid complete closing of the valve 12.

Final complete closing of the valve 12 is eflected by the introduction of pressure fluid through port 39 into the space 44 between main piston 28 and abutment piston 34. Should the operative fluid pressure fail during such operation the valve will be closed by the spring 30, and emergency operation of the valve 12 can thereafter be eflected with the aid of the handwheel 58.

If the tank is to be used for ballast-water, given that the valve 12 is fully closed, valve 11 can be operated to place ballast-water chamber 1 into and out of communication with chamber 3 by a sequence of operations upon the main piston 27 and abutment piston 33 in cylinder 19 similar to that previously described with reference to valve 12.

When heavy pressures in the liquid flow circuits are to be dealt with, the valves 11 and 12 may be provided at the rear with axially directed skirts 63 and 64 which are a sliding liquid-tight fit within axially directed cylindrical projections 65 and 66 on the detachable parts 17 and 18 of the outer walls of the chambers 1 and 2, sealing gaskets such as 0 rings 67 and 68 being interposed between the skirts and the cylindrical projections.

Passages 69, 7t} lead through the heads of the valves 11 and 12 to the respective spaces enclosed by the skirts and cylindrical projections so that liquid from the chamber 3 can enter and fill those spaces whereby a state of substantial pressure balance is achieved between the two sides of the heads of the respective valves 11 and 12. By this means the pressure of operative fluid required to open or close the valves may be kept low.

I claim:

1. A valve-control structure comprising a cylinder, first and second end closures for the two ends of said cylinder, a valve member including a valve head and a valve stem mounted with the valve head at the exterior of the first of said end closures and with the valve stem sliding axially of said cylinder and guided in atleast one of said end closures, a main piston in said cylinder fixedly mounted on said'valve stern and defining with said first of said end closures a first closed space for pressure fluid within said cylinder, an abutment piston in said cylinder movable in a direction to effect partial closing of said valve member, said abutment piston being guided and slidable on said valve stem and defining with the second of said end closures a second closed space separate from said first closed space for pressure fluid within the cylinder and defining with the said main piston a third closed space separate from said first and second closed spaces for pressure fluid within the cylinder, stop means within said third space limiting the extent of movement permitted to said abutment piston in the cylinder in the valve-closing direction and spring means in said third space and between said stop means and said main piston biasing said main piston in the direction away from said abutment piston and a plurality of separate ports by which pressure fluid may be selectively applied to said first, second and third closed spaces respectively.

2. A valve-control structure as claimed in claim I having an extension of said valve stem extending through and beyond the cylinder end closure adjacent the said abutment piston, and a movable hand control on the structure movable between an inoperative position and an operative position in connected engagement with said extension of said valve stem beyond said cylinder end closure for opening and closing the valve by hand.

3. A valve-control structure comprising a cylinder, first and second end closures for the two ends of said cylinder, a valve member including a valve head and a valve stem mounted with the valve head at the exterior of the first of said end closures and with the valve stem sliding axially of said cylinder and guided in said first and second end closures, a main piston in said cylinder fixedly mounted on said valve stem and defining with said first of said end closures a first closed space for pressure fluid within said cylinder, an abutment piston in said cylinder movable in a direction to elfect partial closing of said valve member, said abutment piston being guided and slidable on said valve stem and defining with the second of said end closures a second closed space separate from said first closed space for pressure fluid within the cylinder and defining with the said main piston a third closed space separate from said first and second closed spaces, for pressure fluid within the cylinder, stop means within said third space limiting the extent of movement permitted to said abtument piston in the cylinder in the valve-closing direction and a compression spring in said third space engaging said stop means and said main piston and biasing said main piston in the direction away from said abutment piston and a plurality of separate ports by which pressure fluid may be selectively applied to said first, second and third closed spaces respectively.

4. A valve chest for controlling the selective introduction or removal of two different liquids into or from a tank, said chest comprising a first chamber for one liquid, at second chamber for the other liquid and a third chamber connected with the tank, a pair of orifices in the walls of the third chamber, ducts leading from the first and second chambers to the respective orifices, a pair of valve members for respectively closing or opening each orifice, each valve member including a valve head Within each duct and a valve stem, an opening in each duct wall opposite the orifice for slidably guiding the valve stem, a cylinder mounted exteriorly of the said opposite duct Wall concentric with the opening wherein the said wall forms a first end closure for the cylinder, a second end closure for the end of the cylinder remote from the first end wall, a main piston in said cylinder fixedly mounted on said valve stem and defining with said first of said end closures a first closed space for pressure fluid within said cylinder, an abutment piston in said cylinder movable in a direction to effect partial closing of said valve member, said abutment piston being guided and slidable on said valve stem and defining with the second of said end closures a second closed space separate from said first closed space for pressure fluid within the cylinder and defining with the said main piston 21 third closed space separate from said first and second closed spaces for pressure fluid Within the cylinder, stop means within said third space limiting the extent of movement permitted to said abutment piston in the cylinder in the valveclosing direction and spring means in said third space and between said stop means and said main piston biasing said main piston in the direction away from said abutment piston and a plurality of separate ports by which pressure fluid may be selectively applied to said first, second and third closed spaces respectively.

5. A valve chest as claimed in claim 4 wherein the said valves are coaxial and move in opposite directions away from one another to the valve-open positions.

6. A valve chest according to claim 4 in which each valve stem is extended through the associated cylinder for slidable movement within an opening in the second end closure.

7. A valve chest according to claim 6 including second valve means controlled by the valve stem associated with one cylinder when its valve head is moved from a position closing its corresponding orifice, for preventing the flow of pressure fluid to the other cylinder for moving its associated valve to open position.

References tlited in the file of this patent UNITED STATES PATENTS 1,926,076 Whalen Sept. 12, 1933 2,068,816 Pratt Jan. 26, 1937 2,142,950 Loefller Jan. 3, 1939 2,608,213 Hruby Aug. 26, 1952 2,712,324 Lund July 5, 1955 2,757,640 White Aug. 7, 1956 2,809,799 Cunningham Oct. 15, 1957 2,840,044 Carrion June 24, 1958 FOREIGN PATENTS 483,835 Great Britain of 1938 

